This invention relates to a signal inspection device for inspection operating function of various electronic devices and more particularly to such a device and a method for testing wherein the operation and inspection device do not require the operation of a personal computer.
Signal inspection devices are used to inspect operational functions of various electronic devices that perform various operations under specified conditions. The signal inspection device is used to judge whether the output of an electronic device is correct by inputting into the electronic device inspection signals commensurate with the use conditions of the electronic device and measuring the output signals produced in response to the input signals.
For this purpose, PC-connected type of signal inspection devices have been conventionally employed. In this method an inspection unit with a electronic device to be tested is placed therein. Then a connection is made to a PC (personal computer) which controls input signals to the electronic device and measures output from the electronic device.
With the PC-connected type of inspection device, measurement and control functions of the inspection are dependent on the performance of the PC. Therefore, stabilized, highly reliable inspection cannot always be made. In addition, the flexibility of such PC-connected type of inspection devices is limited. For example, if a special control is required for each inspection item, for example a temporary stop time control for a very short time, such as in microseconds, before performing measurement, control functions must be set according to the operating system software of the PC. This requires detailed, special knowledge about the operation system of the PC. As a result, considerable time is required before the measurement and control are actually performed. Also with the PC-connected type of inspection device, if an accidental stop of the PC operation due to incorrect operation or failure of the PC further problems arise. To resolve them requires special knowledge of the operating system of the PC. This increases personnel costs, adds to time and trouble of maintenance, and lowers the rate of operation and productivity.
Another type of signal inspection device that has been conventionally in use employs a read only memory (ROM) that cannot be rewritten and in which an inspection program is written from outside the inspection device. The ROM is then mounted on a CPU board (control circuit) of an inspection unit. Inspection signals are inputted according to the inspection program of the ROM and the output signals are detected.
A problem with inspection devices using a ROM is their flexibility is limited because the inspection program cannot be easily rewritten. To rewrite the inspection program of the ROM, requires special knowledge and apparatus.
It is therefore a principal object of this invention to provide a signal inspection device and method where measurement and inspection can be performed without being affected by the performance of a PC.It is a further object of the invention to provide a signal inspection device and method where the inspection program can be easily rewritten without requiring special knowledge of the operating system of a PC.It is a still further object of the invention to provide a signal inspection device and method where changes in the electronic device to be inspected can be easily made.